scholarly journals Compensatory plasticity in the olfactory epithelium: age, timing, and reversibility

2015 ◽  
Vol 114 (3) ◽  
pp. 2023-2032 ◽  
Author(s):  
Casey N. Barber ◽  
David M. Coppola
Keyword(s):  
Nasal Cavity ◽  
Olfactory Epithelium ◽  
Adult Mouse ◽  
Olfactory Receptor Neurons ◽  
Nasal Airflow ◽  
Stimulus Response ◽  
Open Side ◽  
Receptor Neurons ◽  
Compensatory Plasticity ◽  
Stimulus Environment

Like other biological systems, olfaction responds “homeostatically” to enduring change in the stimulus environment. This adaptive mechanism, referred to as compensatory plasticity, has been studied almost exclusively in developing animals. Thus it is unknown if this phenomenon is limited to ontogenesis and irreversible, characteristics common to some other forms of plasticity. Here we explore the effects of odor deprivation on the adult mouse olfactory epithelium (OE) using nasal plugs to eliminate nasal airflow unilaterally. Plugs were in place for 2–6 wk after which electroolfactograms (EOGs) were recorded from the occluded and open sides of the nasal cavity. Mean EOG amplitudes were significantly greater on the occluded than on the open side. The duration of plugging did not affect the results, suggesting that maximal compensation occurs within 2 wk or less. The magnitude of the EOG difference between the open and occluded side in plugged mice was comparable to adults that had undergone surgical naris occlusion as neonates. When plugs were removed after 4 wk followed by 2 wk of recovery, mean EOG amplitudes were not significantly different between the always-open and previously plugged sides of the nasal cavity suggesting that this form of plasticity is reversible. Taken together, these results suggest that compensatory plasticity is a constitutive mechanism of olfactory receptor neurons that allows these cells to recalibrate their stimulus-response relationship to fit the statistics of their current odor environment.

Neuronal nitric oxide synthase-like immunoreactivity in olfactory epithelium throughout the life cycle of the sea lamprey, Petromyzon marinus L.

2000 ◽  
Vol 78 (3) ◽  
pp. 346-351 ◽  
Author(s):  
Hong N Hua ◽  
Aliya U Zaidi ◽  
Barbara S Zielinski
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Olfactory Epithelium ◽  
Olfactory Receptor ◽  
Petromyzon Marinus ◽  
Neuronal Nitric Oxide Synthase ◽  
Sea Lamprey ◽  
Olfactory Receptor Neurons ◽  
Receptor Neurons ◽  
Oxide Synthase

This study is the first to show that neuronal nitric oxide synthase-like immunoreactivity is located in the olfactory epithelium at all developmental stages of a vertebrate. Western immunoblotting of sea lamprey (Petromyzon marinus L.) olfactory mucosa with a monoclonal antibody against the NADPH-binding epitope of neuronal nitric oxide synthase showed that the molecular mass of this protein was 200 kDa. In the larval stage, neuronal nitric oxide synthase-like immunoreactivity was strongest in the basal region of the olfactory epithelium, the site of proliferating olfactory receptor neurons. This staining gradually diminished as the life cycle progressed. In the juvenile stage, the intensity of neuronal nitric oxide synthase-like immunoreactivity was striking in the wide cell bodies and dendrites on olfactory receptor neurons. These results confirm previous evidence that nitric oxide modulates development in the olfactory epithelium.

Primary Culture of Adult Mouse Olfactory Receptor Neurons

1998 ◽  
Vol 151 (2) ◽  
pp. 173-183 ◽  
Author(s):  
N. Liu ◽  
C.B. Shields ◽  
F.J. Roisen
Keyword(s):  
Primary Culture ◽  
Olfactory Receptor ◽  
Adult Mouse ◽  
Olfactory Receptor Neurons ◽  
Receptor Neurons

scholarly journals Comparison of the Nasal Olfactory Organs of Various Species of Lizardfishes (Teleostei: Aulopiformes: Synodontidae) with Additional Remarks on the Brain

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
L. Fishelson ◽  
D. Golani ◽  
B. Galil ◽  
M. Goren
Keyword(s):  
Olfactory Epithelium ◽  
Olfactory Receptor ◽  
Olfactory Receptor Neurons ◽  
Adult Fish ◽  
Supporting Cells ◽  
Receptor Neurons ◽  
Olfactory Organs ◽  
Species Specific ◽  
The Brain

The olfactory organs of lizardfishes (Synodontidae) are situated in two capsules connected to the outside by incurrent and excurrent openings. The olfactory epithelium is in form of petal rosettes each composed of lamellae and a rephe, and bear olfactory receptor neurons, supporting cells and cells with kinocillia. The dimension of rosettes and lamellae, as well as the number of lamellae, increase with growth of the fish; until in adult fish these parameters remaine constant, species specific. In adultSynodusspp. andTrachinocephalus myopsthe rosettes are 3.5–4.0 mm long, with 5–8 lamellae, whereas inSauridaspp. they are 8.0 mm and possess up tp 22 lamellae. The number of ORN ranges from 2,600 on the smaller lamellae to 20,000 on the largest ones. The number of ORN/m of olfactory is ca. 30,000 inSauridaspp. Thus the rosettes ofS. macrolepiswith 20 lamellae possess a total of ca. 170,000 ORN, whereas those ofSy. variegatusandT. myopswith the average of six lamellae possess only ca. 50,000–65,000 ORN. The olfactory nerves lead from the rosettes to the olfactory balbs situated on the olfactory lobes. The differences among the species in olfactory organs are discussed in correlation with their distribution.

scholarly journals Evidence of SARS-CoV2 entry protein ACE2 in the human nose and olfactory bulb

2020 ◽  
Author(s):  
M. Klingenstein ◽  
S. Klingenstein ◽  
P.H. Neckel ◽  
A. F. Mack ◽  
A. Wagner ◽  
...  
Keyword(s):  
Olfactory Bulb ◽  
Olfactory Epithelium ◽  
Olfactory Receptor ◽  
Respiratory Epithelium ◽  
Olfactory Receptor Neurons ◽  
Basal Cells ◽  
Sustentacular Cells ◽  
Glandular Cells ◽  
Receptor Neurons ◽  
Human Nose

ABSTRACTUsually, pandemic COVID-19 disease, caused by SARS-CoV2, presents with mild respiratory symptoms such as fever, cough but frequently also with anosmia and neurological symptom. Virus-cell fusion is mediated by Angiotensin-Converting Enzyme 2 (ACE2) and Transmembrane Serine Protease 2 (TMPRSS2) with their organ expression pattern determining viral tropism. Clinical presentation suggests rapid viral dissemination to central nervous system leading frequently to severe symptoms including viral meningitis. Here, we provide a comprehensive expression landscape of ACE2 and TMPRSS2 proteins across human, post-mortem nasal and olfactory tissue. Sagittal sections through the human nose complemented with immunolabelling of respective cell types represent different anatomically defined regions including olfactory epithelium, respiratory epithelium of the nasal conchae and the paranasal sinuses along with the hardly accessible human olfactory bulb. ACE2 can be detected in the olfactory epithelium, as well as in the respiratory epithelium of the nasal septum, the nasal conchae and the paranasal sinuses. ACE2 is located in the sustentacular cells and in the glandular cells in the olfactory epithelium, as well as in the basal cells, glandular cells and epithelial cells of the respiratory epithelium. Intriguingly, ACE2 is not expressed in mature or immature olfactory receptor neurons and basal cells in the olfactory epithelium. Similarly ACE2 is not localized in the olfactory receptor neurons albeit the olfactory bulb is positive. Vice versa, TMPRSS2 can also be detected in the sustentacular cells and the glandular cells of the olfactory epithelium.Our findings provide the basic anatomical evidence for the expression of ACE2 and TMPRSS2 in the human nose, olfactory epithelium and olfactory bulb. Thus, they are substantial for future studies that aim to elucidate the symptom of SARS-CoV2 induced anosmia of via the olfactory pathway.

scholarly journals Lineage, Identity, and Fate of Distinct Progenitor Populations in the Embryonic Olfactory Epithelium

2021 ◽  
Author(s):  
Elizabeth M Paronett ◽  
Corey A Bryan ◽  
Thomas M Maynard ◽  
Anthony-S. LaMantia
Keyword(s):  
Olfactory Epithelium ◽  
Olfactory Nerve ◽  
Late Gestation ◽  
Olfactory Receptor Neurons ◽  
Proliferative Capacity ◽  
Temporal Dimension ◽  
Sustentacular Cells ◽  
Distinct Cell ◽  
Receptor Neurons ◽  
Temporal And Spatial

We defined a temporal dimension of precursor diversity and lineage in the developing mouse olfactory epithelium (OE) at mid-gestation that results in genesis of distinct cell classes. Slow, symmetrically dividing Meis1+/ Pax7+ progenitors in the early differentiating lateral OE give rise to small numbers of Ascl1+ precursors in the dorsolateral and ventromedial OE. Few of the initial progeny of the Ascl1+ precursors immediately generate olfactory receptor neurons (ORNs). Instead, most early progeny of this temporally defined precursor cohort, labeled via temporally discreet tamoxifen-dependent Ascl1Cre-driven recombination, populate a dorsomedial OE domain comprised of proliferative Ascl1+ as well as Ascl1- cells from which newly generated ORNs are mostly excluded. The most prominent early progeny of these Ascl1+ OE precursors are migratory mass cells associated with the nascent olfactory nerve (ON) in the frontonasal mesenchyme. These temporal, regional and lineage distinctions are matched by differences in proliferative capacity and modes of division in isolated, molecularly distinct lateral versus medial OE precursors. By late gestation, the progeny of the temporally and spatially defined Ascl1+ precursor cohort include few proliferating precursors. Instead, these cells generate a substantial subset of OE sustentacular cells, spatially restricted ORNs, and ensheathing cells associated with actively growing as well as mature ON axons. Accordingly, from the earliest stages of OE differentiation, distinct temporal and spatial precursor identities provide a template for acquisition of subsequent OE and ON cellular diversity.

scholarly journals Neuronal Chloride Accumulation in Olfactory Epithelium of Mice Lacking NKCC1

2006 ◽  
Vol 95 (3) ◽  
pp. 2003-2006 ◽  
Author(s):  
William T. Nickell ◽  
Nancy K. Kleene ◽  
Robert C. Gesteland ◽  
Steven J. Kleene
Keyword(s):  
Olfactory Epithelium ◽  
Electrical Response ◽  
Niflumic Acid ◽  
Olfactory Receptor Neurons ◽  
Flufenamic Acid ◽  
Wild Type ◽  
In The Wild ◽  
Receptor Neurons ◽  
Chloride Accumulation

When stimulated with odorants, olfactory receptor neurons (ORNs) produce a depolarizing receptor current. In isolated ORNs, much of this current is caused by an efflux of Cl−. This implies that the neurons have one or more mechanisms for accumulating cytoplasmic Cl− at rest. Whether odors activate an efflux of Cl− in intact olfactory epithelium, where the ionic environment is poorly characterized, has not been previously determined. In mouse olfactory epithelium, we found that >80% of the summated electrical response to odors is blocked by niflumic acid or flufenamic acid, each of which inhibits Ca2+-activated Cl− channels in ORNs. This indicates that ORNs accumulate Cl− in situ. Recent evidence has shown that NKCC1, a Na+-K+-2Cl− cotransporter, contributes to Cl− accumulation in mammalian ORNs. However, we find that the epithelial response to odors is only reduced by 39% in mice carrying a null mutation in Nkcc1. As in the wild-type, most of the response is blocked by niflumic acid or flufenamic acid, indicating that the underlying current is carried by Cl−. We conclude that ORNs effectively accumulate Cl− in situ even in the absence of NKCC1. The Cl−-transport mechanism underlying this accumulation has not yet been identified.

scholarly journals PACAP Is Present in the Olfactory System and Evokes Calcium Transients in Olfactory Receptor Neurons

2003 ◽  
Vol 90 (4) ◽  
pp. 2711-2719 ◽  
Author(s):  
Colleen C. Hegg ◽  
Edmund Au ◽  
A. Jane Roskams ◽  
Mary T. Lucero
Keyword(s):  
Olfactory Epithelium ◽  
Olfactory Receptor ◽  
Olfactory Receptor Neurons ◽  
Olfactory Ensheathing Cells ◽  
Adult Mice ◽  
Supportive Role ◽  
Ensheathing Cells ◽  
Key Factor ◽  
Mature Neurons ◽  
Receptor Neurons

Pituitary adenylate cyclase activating peptide (PACAP), a neuroregulatory peptide, is found in germinative regions of the CNS, including the olfactory bulb, throughout adulthood. We show that 1) PACAP immunoreactivity is also present in the neonatal mouse and adult mouse and rat olfactory epithelium, 2) PACAP expression pattern differs between neonatal and adult mice, and 3) PACAP is produced by olfactory ensheathing cells. PACAP may thus be a key factor in the uniquely supportive role of olfactory ensheathing cells in regeneration of neurons from olfactory epithelium and lesioned spinal cord. Using calcium imaging, we demonstrated physiological responses to PACAP in both neonatal and adult olfactory receptor neurons (ORNs). We propose that PACAP plays an important role in normal turnover of ORNs by providing neurotrophic support during development and regeneration and neuroprotective support of mature neurons.

Odorant Concentration Dependence in Electroolfactograms Recorded From the Human Olfactory Epithelium

2009 ◽  
Vol 102 (4) ◽  
pp. 2121-2130 ◽  
Author(s):  
Hadas Lapid ◽  
Han-Seok Seo ◽  
Benno Schuster ◽  
Elad Schneidman ◽  
Yehudah Roth ◽  
...  
Keyword(s):  
Concentration Dependence ◽  
Olfactory Epithelium ◽  
Olfactory Receptor ◽  
Isovaleric Acid ◽  
Valeric Acid ◽  
Olfactory Receptor Neurons ◽  
Olfactory Coding ◽  
Perceived Intensity ◽  
Receptor Neurons

Electroolfactograms (EOGs) are the summated generator potentials of olfactory receptor neurons measured directly from the olfactory epithelium. To validate the sensory origin of the human EOG, we set out to ask whether EOGs measured in humans were odorant concentration dependent. Each of 22 subjects (12 women, mean age = 23.3 yr) was tested with two odorants, either valeric acid and linalool ( n = 12) or isovaleric acid and l-carvone ( n = 10), each delivered at four concentrations diluted with warm (37°C) and humidified (80%) odorless air. In behavior, increased odorant concentration was associated with increased perceived intensity (all F > 5, all P < 0.001). In EOG, increased odorant concentration was associated with increased area under the EOG curve (all F > 8, all P < 0.001). These findings substantiate EOG as a tool for probing olfactory coding directly at the level of olfactory receptor neurons in humans.

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